Research Comparison
IGF-1 LR3 (Long R3 IGF-1) vs Ipamorelin
A side-by-side research comparison of IGF-1 LR3 (Long R3 IGF-1) and Ipamorelin drawn from Cedar Peptides' peptide database records.
IGF-1 LR3 (Long R3 IGF-1)
IGF-1 LR3 is a synthetic 83-amino acid analog of insulin-like growth factor-1 (IGF-1), modified with an arginine substitution at position 3 and an extended N-terminal sequence. These modifications significantly reduce binding to IGF-binding proteins (IGFBPs), resulting in prolonged circulation and increased bioavailability. Unlike native IGF-1, which has a short half-life, IGF-1 LR3 exhibits a substantially extended half-life (~20–30 hours), allowing sustained activation of IGF-1 receptors. Despite its potency and widespread research use, it has never been approved for human use and lacks clinical trial data, remaining strictly a research compound.
Ipamorelin
Ipamorelin is a selective growth hormone releasing peptide (GHRP) that stimulates endogenous growth hormone (GH) secretion via activation of ghrelin (GHS-R1a) receptors in the pituitary. It is characterized by a highly selective profile, producing GH release without significant stimulation of cortisol or prolactin. This selectivity distinguishes it from earlier GHRPs, making it a preferred compound in research focused on body composition, recovery, sleep, and anti-aging. Its ability to preserve physiological GH pulsatility while minimizing off-target endocrine effects has positioned it as a core peptide in GH optimization protocols.
Reading a comparison
A comparison places two records side by side; it does not merge them. Each description above is drawn from that compound's own record, and the two were not necessarily characterised by the same methods, at the same time, or to the same level of detail. Before comparing any attribute, it is worth establishing that both records describe the substance you think they describe — names are not identifiers, and two entries sharing a name can differ in salt form, stereochemistry or the convention used to state a mass. Where a figure carries no method beside it, the comparison is between two reported numbers rather than between two measurements.